Last March, I've tried to upload BITNA service(sort of web service for smartphone app) on world-wide Amazon EC2 servers. In that process, for checking latency, I wrote a memo regards ping latency and HTTP latency(specific page that returns kind of 'hello world'). Certainly, it's not pretty precise time and based on Korea's network environment, but I believe that you might need this data for your reference.
GAE(HTTP) is HTTP request/response latency, and others are ping request/response latency. (unit is ms) Surely, GAE means Google App Engine. This result shows HTTP latency is pretty much, as compared to ping latency.
to
from | GAE | GAE(HTTP) | Site A* | Site B** |
| EC2(Oregon) | 20~30 | 118~ | 228~ | 179~ |
| EC2(Singapore) | 9~15 | 261~ | 116~ | 122~ |
| EC2(Tokyo) | 32~34 | 254~ | 48~ | 52~ |
| EC2(Ireland) | 21 | 117~ | 380~ | 313~ |
| EC2(Virginia) | 2~4 | 16~ | 200~ | 240~ |
| *** KT wibro | 130~190 | 320~ | 88~ | 95~ |
| *** KT 3G | 300~ | 380~ | ||
| Cable Internet**** | 45~52 | 280~ |
* web-hosting type site in Korea
** virtual host type site in Korea
*** KT wibro and KT 3G are mobile internet service of Korean company KT.
**** Cable network ISP in Seoul, Korea
